The invention relates to antivibration devices and to mechanical assemblies including such devices.
More particularly, the invention relates to an antivibration device including:
an antivibration mount having a first rigid strength member designed to be fastened to a vehicle chassis, a second rigid strength member and an elastomer body interposed between said first and second strength members, said elastomer body being designed to withstand a permanent compression effort in a vertical direction and to damp vibrations at least in said vertical direction, said second strength member including two lateral ears which protrude laterally from said elastomer body and which are pierced respectively by two parallel holes;
and a motor bracket extending between a first end which is designed to be fastened to a vehicle motor and a second end which is designed to be fastened to said ears by screwing.
In known antivibration devices of this type, the second end of the motor bracket is fastened to the ears of the second strength member by means of a screw which extends horizontally.
Since this screw is fastened inside the motor compartment of the vehicle after the motor (already fastened to the motor bracket) has been positioned in said compartment, the fastening of this screw is uneasy and therefore lengthy and costly.
Furthermore, the motor bracket does not bear on the second strength member before the fastening of the screw, which renders more difficult the process of assembling the motor bracket to antivibration mount.
A particular object of the present invention is to remedy these drawbacks by providing an antivibration device of the kind in question which is simpler, cheaper and easier to assemble than the known antivibration devices.
To this end, according to the invention, the second end of the motor bracket includes two parallel branches each having a reception housing which is open downward, said reception housings being designed to receive respectively the two lateral ears of the second strength member of the antivibration mount, and each of said branches having a hole which is designed to register with the hole of the corresponding ear to receive a fastening screw when the motor bracket is assembled to the antivibration mount. Thanks to these dispositions, the motor bracket bears on the antivibration mount as soon as said motor bracket is positioned on said mount, even before fastening the screws, which eases the assembling process.
Further, the direction of the holes of the branches of the motor bracket and of the ears of the antivibration mount enables an easy access for fastening the screws in said holes.
In preferred embodiments of the antivibration device according to the invention, one may possibly use in addition one and/or other of the following arrangements:
the holes of the branches of the motor bracket and of the ears of the antivibration mount are oriented in a direction extending slantwise, upwardly away from the first end of the motor bracket;
each reception housing is delimited at least by first and second secant upper receiving surfaces diverging downward, the first receiving surface sloping downward toward the first end of the motor bracket and the second receiving surface extending substantially perpendicular to the direction of the holes, and each ear of the antivibration mount including first and second bearing surfaces having complementary shapes to said first and second receiving surfaces;
the reception housings of the motor bracket are further delimited respectively by two lateral receiving surfaces which diverge slantwise in a direction opposite to the first end of the motor bracket, said lateral receiving surfaces being designed to be in contact respectively with the two ears of the antivibration mount opposite the elastomer body;
the reception housings are open toward each other;
the first receiving surface of each reception housing includes a protruding lip and the corresponding ear of the antivibration mount fits between said lateral receiving surface and said lip;
the hole of each ear of the antivibration mount is threaded;
the first end of the motor bracket includes a fastening plate including fastening holes designed to receive screws for fastening said motor bracket to the motor;
the first strength member of the antivibration mount has a rigid yoke extending around said elastomer body between the ears of the second strength member, said yoke being designed to de positioned between said two branches of the motor bracket;
the direction of the holes of the branches of the motor bracket and of the ears of the antivibration mount makes an angle of between 30xc2x0 and 60xc2x0 with a horizontal direction.
Another object of the present invention is a mechanical assembly comprising:
a vehicle motor;
a vehicle chassis;
an antivibration mount having a first rigid strength member fastened to the vehicle chassis, a second rigid strength member and an elastomer body interposed between said first and second strength members, said elastomer body withstanding a permanent compression effort in a vertical direction and being designed to damp vibrations at least in said vertical direction, said second strength member including two lateral ears which protrude laterally from said elastomer body and which are pierced respectively by two parallel holes;
and a motor bracket extending between a first end which is fastened to a vehicle motor and a second end which is fastened to said ears by screwing;
wherein the second end of the motor bracket includes two parallel branches each having a reception housing which is open downward, said reception housings receiving respectively the two lateral ears of the second strength member of the antivibration mount, and each of said branches having a hole which registers with the hole of the corresponding ear, two fastening screws traversing respectively said holes of the branches of the motor bracket and being received in said holes of the ears, the holes of the branches of the motor bracket and of the ears of the antivibration mount being oriented in a direction extending slantwise upwardly away from the first end of the motor bracket.
In preferred embodiments of the mechanical assembly according to the invention, one may possibly use in addition one and/or other of the following arrangements:
each reception housing is delimited at least by first and second secant upper receiving surfaces diverging downward, the first receiving surface sloping downward toward the first end of the motor bracket and the second receiving surface extending substantially perpendicular to the direction of the holes, and each ear of the antivibration mount including first and second bearing surfaces having complementary shapes to said first and second receiving surfaces;
the reception housings of the motor bracket are further delimited respectively by two lateral receiving surfaces which diverge slantwise in a direction opposite to the first end of the motor bracket, said lateral receiving surfaces being in contact respectively with the two ears of the antivibration mount opposite the elastomer body.